- Type THHN or THWN-2* conductors are primarily used in conduit and cable trays for services, feeders, and branch circuits in commercial or industrial applications as specified in the National Electrical Code2.
- When used as Type THHN, conductor is suitable for use in dry locations at temperatures not to exceed 90°C.
- When used as Type THWN-2*, conductor is suitable for use in wet or dry locations at temperatures not to exceed 90°C or not to exceed 75°C when exposed to oil or coolant.
- When used as Type MTW, conductor is suitable for use in wet locations or when exposed to oil or coolant at temperatures not to exceed 60°C or dry locations at temperatures not to exceed 90°C (with ampacity limited to that for 75°C conductor temperature per NFPA 79).
- Conductor temperatures not to exceed 105°C in dry locations when rated AWM and used as appliance wiring material. Voltage for all applications is 600 volts.
- UL Standard 83
- UL Standard 1063 (MTW)
- Federal Specification
- A-A-59544, and requirements of the National Electrical Code.
Standards: THHN or THWN-2* or MTW (also AWM) meets or exceeds all applicable ASTM specifications
THWN and THHN Wire for Sale
THHN and THWN cables are tray and conduit feeder wires used in branch circuits of commercial or industrial applications. They can also serve as control wires in smaller set-ups; small sized cables used to detect changes and control systems. They are designed to a gauge size of 250 to 1000 MCM and specifically used for transmission and distribution of 600V power. The cable is extensively used various control systems like automotive plants, wind energy, forestry equipment, oil and petroleum equipment, among many more.
Since it has a wide range of applications, the cable is designed such as to ensure efficient current transmission, secure insulation and stable functionality. It is therefore constructed to outstanding specifications which befits the systems of applications. You can buy thhn wire online or from a reliable wire store. However, it is important to know a few attributes of the thhn wire for sale in order to make an informed decision and consequently get quality products for your money. With money-hungry cable and wire products suppliers all over, you can never be too careful these days. Here are some ideal attributes of a good thhn wire.
THHN wire Conductor
THHN like THWN wires are constructed using copper conductors. Copper is widely used for these control cables because it has excellent electrical properties. Copper is an excellent conductor, strong, hard enough to prevent nicks and also flexible; it entails everything you’d want in a flexible portable control wire. However, it has some drawbacks and the conductor used in this cable is modified to make it more stable and fit. The modification includes annealing to make it soft and stranding to improve its flexibility and electrical conductivity. The Copper conductor is fully annealed, stranded and bare according to ASTM B3 and ASTM B8. The number of stranding range from 7 to 19 strands while conductors range from 3 to 4.
THHN Wire Insulation
When you buy a THHN wire online, ensure that it has a Polyvinyl Chloride (PVC) insulation which is flame retardant and has clear Polyamide (nylon). Since the cable is to be used in harsh conditions such as in direct burial, it requires a strong, stable and reliable insulation. PVC insulation serves best, it keeps off destructive agents and maintains the conductor structure. The insulation color coding is as per ICEA Method 4.
THHN Wire Jacket
Cable jackets are additional security features which also contain the components of the cable. They complement the insulations to ensure the conductor security is tighter. The Tray Control cable has its jacket made of Polyvinyl Chloride (PVC) with a thickness of about 60 mils. The thicker the jacket the more secure though it causes bulkiness but this jacket doesn’t exceed 60 mils hence less bulky. This jacket system is lead-free, sunlight and flame resistant and environmental friendly.
Tray Control cable has distinctive features:
• It has a Ripcord
• A 600V rating
• Has THHN or THWN Insulation.
• PVC Jacket
• Copper conductors.
• Excellent resistance to oil, chemical and sunlight.
• Resistance to cold bends and cold impacts
• Tray Control cable has the smallest cable Outer Diameter required for suitable applications
• The crush and impact requirements that this cable has are of Type MC Cable.
• It has a color code according to ICEA Method 4
Tray control cable is used in various industrial plants. Generally, the purpose for the cable is power transmission in control systems and in lighting circuits. It is used broadly in the commercial and industrial applications. Some of the industrial plants where it is applied include: oil and petroleum equipment, processing equipment, packaging facilities, automotive plants and wind energy. The cable is also used in tray wiring, cold temperature storage systems and machine tool wiring.
This cable can be used above ground, on raceways or direct burial method. Since it has the capacity to withstand both extreme climates of wet and dry locations, this cable serves well in either of the installation methods. Install it indoors or outdoors, in aerial systems or conduits, in cable ducts, cable trays or directly buried provided the circuit voltage exceeds not 600 volts.
The cable has passed the flame tests by IEEE and is also resistant to oil and other chemicals. These make it sturdy, strong and reliable when used in control systems for oil industries where chances for fire outbreaks are high. Its high flexibility befits it for wind energy and automotive plants where movements are frequent. With high electrical conductivity and stability to temperature variance, the cable makes a good control system.
One thing you have to be keen on before you buy a THHN Wire is its temperature approvals, lest you buy a cable that will succumb to adverse effects of the environment. A good THHN cableshould be approved for effective operation at 900C in dry locations and 750C in wet places. It can sustain a temperature of up to 1300C during emergency overload and 2500C for short circuit conditions. The cable is rated at 600 V.
Approvals and Certifications
• UL approved for use continuously in the above mentioned conditions
• Approved for direct burial
• May be used in NEC Class I and II systems
• May be used in Division 2 hazardous locations
• Allowed for Exposed Run (ER) and be used accordance with NEC
We hope that you’ll find this information valuable when you buy THHN wire online. Basically, the same features apply when you buy THWN wire online. Nassau National offers buy thhn and thwn wire for sale online. To order your thhn wires online, please visit our website today!
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Frequently Asked Questions - THHN THWN-2 Copper Conductor Building Wire
What does “THHN” and “THWN” stand for?
- T - Stands for Thermoplastic insulation.
- HH – Has a higherheat resistance
- N – Indicates that the wire is nylon coated. Copper wires that are stranded and solid can have a mechanical coating of nylon which protects them from oil and gas.
- H – A single H just indicated that it is resistant to heat but it cannot match the resistance that is given by HH.
- W – It is resistant to water and moisture. So it can be used in both wet and dry locations.
What is the maximum working temperature for THHN THWN-2 Copper Conductor Building Wire?
You can use the wire up to a temperature of 90°C when used as a Type THHN. The maximum temperature for Type THWN-2 is also 90°C. However, when the wire is used in industries where it can be exposed to oil or coolant, then care must be taken to ensure that the maximum working temperature is 75°C or below.
How is the THHN THWN-2 Copper Conductor Building Wire constructed?
The copper conductorsare made with soft annealed copper, which are insulated with PVC insulation. This makes the conductors resistant to extreme heat and moisture. Then there is an overall jacket that has a nylon jacket.
Where can you use the THHN THWN-2 Copper Conductor Building Wire?
You can use the conductor for all types of services and feeders in both commercial and industrial applications. The conductor is also ideal for use in branch circuits in conduit and cable trays. When used as a Type THWN-2, it can be used in both wet and dry locations.
What are the standards and references that are met by the THHN THWN-2 Copper Conductor Building Wire?
The Type THHN and THWN meet the following specifications –
- UL Standard 83
- Federal Specification A-A-59544
- National Electrical Code
Can I use the Type THHN THWN-2 Copper Conductor Wire for lamp posts instead of a UF wire?
Ideally, people use a UF wire for lamp posts, but you can also use the Type THHN THWN-2 for it. You can just run it inside the lamp post but you must have a conduit. The conduit must come above the ground either inside the lamp post itself or next to it. Also, please note that underground conduits are considered as wet locations. So you will have to use a splice method suitable for wet locations even if the conduit is dry.